The present invention relates generally to image displays.
Image displays include emissive displays, such as phosphor displays used in cathode tube-based television and computer monitors, and transmissive displays, such as projection displays used for large screen TVs. An emissive display works by emitting visible light from pixels that are excited by, e.g., electron beams or fluorescent lamps. In the case of conventional electron beam-based displays, the electron beam is scanned across the pixels as appropriate to excite the pixels to produce a demanded image. In the case of fluorescent lamp-based displays such as plasma displays, ultraviolet light from a gas discharge is directed to appropriate pixels that are physically shielded from each other, with the pixel illumination pattern necessary to produce the demanded image not being established by scanning the UV light, which is simply a discharge from the lamp, but by appropriately blocking the UV light to impinge only on the desired pixels. Both of the above-mentioned emissive displays require the presence of a vacuum within the device, which can complicate manufacturing and raise costs.
Because the weight of some emissive displays becomes infeasibly large in the case of large screen displays, e.g., displays having sizes of 40xe2x80x3-60xe2x80x3 or more, the above-mentioned transmissive displays have been provided, an example of which is the projection display. A projection display works by projecting pixellated light from a relatively small source onto a relatively large projector, which xe2x80x9ctransmitsxe2x80x9d the light toward the viewers.
As recognized herein, while effective, large screen projection-type displays suffer from the drawback of relatively low image quality, compared to the image quality afforded by a smaller emissive display. On the other hand, current emissive display technology, as noted above, cannot easily be used to establish large screen displays owing to weight and other practical restrictions. Nevertheless, the present invention recognizes that it would be desirable to provide a large screen emissive display to overcome the image quality drawback of many large transmissive displays.
An image display apparatus includes an emissive display having plural pixels, and a source of ultraviolet (UV) light. A pixel activation mechanism scans the UV light onto the pixels in response to a demanded image. The display includes a substrate on which plural pixels are established, with each pixel being established by respective red, green, and blue subpixels. At least one light refracting layer covers the pixels.
Preferably, the pixel activation mechanism directs first, second, and third UV beams against the refracting layer at respective first, second, and third angles. The first, second, and third beams are refracted by the refracting layer only onto respective red, green, and blue subpixels. If desired, a color selection mask layer can be juxtaposed with the refracting layer for shielding the blue and green subpixels from the first beam, shielding the red and green subpixels from the second beam, and shielding the red and blue subpixels from the third beam. The display can be a large screen phosphor display that operates at atmospheric pressure.
In another aspect, a method for producing a demanded image includes receiving the demanded image, and based on the demanded image, directing first, second, and third excitation beams onto a refraction layer associated with a display such that the first beam is refracted onto red subpixels of the display, the second beam is refracted onto green subpixels of the display, and the third beam is refracted onto blue subpixels of the display.
In yet another aspect, a video display apparatus for presenting a demanded image includes a phosphor display operating at atmospheric pressure, and a UV laser beam source. Pixel activation means direct respective first, second, and third beams from the laser beam source onto the display to activate respective red, blue, and green subpixels of the display. At least one light refracting layer covers the pixels.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: